Known shelving systems having mobile shelf units comprise a number of side-by-side shelf units each having a frame supporting a number of shelves. The shelf units are more particularly carried on ground rails that allow the shelf units to be displaced along the rails. A driving mechanism is used to move the shelf units along the rails. Manual and automatic driving mechanisms exist; in the automatic driving mechanisms, each shelf unit is powered for selective autonomous and independent displacement along the rails.
The mobile shelving systems equipped with automatic driving mechanisms conventionally allow the shelf units to be positioned adjacent to one another while freeing a single lane between two selected shelf-units. This lane will allow the passage therein of a person desiring to recuperate an article stored in the shelf units that are immediately adjacent to the lane. The other shelf units are horizontally stacked against each other on one side and the other of the lane, and if access to another shelf unit is required, the shelf units can be displaced along the rails to re-arrange the horizontal stacking of the shelf units, thereby eliminating the previous lane and forming a new lane next to the shelf unit to which access is desired. Consequently a minimal volume is occupied by the shelving system since a lane is not required between each two successively adjacent shelf units: a single open lane will instead be formed between two selected shelf units, while the others remain horizontally stacked.
Prior art automatic shelf units comprise a powered driving system which requires the mobile shelf units to be fed with electricity through electrically conducting wires or power cords. Due to the mobile nature of the shelf units, these power cords are conventionally connected to the shelf units by means of a number of hinged wire support arms. Each support arm comprises two bars pivotally connected to each other and each pivotally connected to a corresponding one of two successively adjacent shelf units. Each support arm supports a power cord that links the two shelf units. A first one of the shelf units is plugged to a power outlet, and consequently all the shelf units are serially connected to the power outlet. Each hinged wire support arm will remain in a contracted, folded position when the two shelf units that it links remain adjacent to each other, while it will be spread open in a deployed, unfolded position when a lane is formed between these two shelf units. The power cords, which are long enough to extend between two spaced-apart shelf units when a lane is formed therebetween, are prevented from sagging between the shelf units by being supported by their corresponding wire support arms.
Also, it is known to provide each shelf unit with an electronic control circuit including an interface device which includes a keyboard and a display screen, a CPU, RAM and ROM memory devices, I/O devices and suitable software components. Each control circuit is connected to the other control circuits, for example by means of a network-type cable, to allow digital communication between the control circuits. The purpose of the control circuits is to allow a control over the position of all mobile shelf units forming a shelving system. More particularly, the position of the shelf units will be controlled so that they move according to the desired position of the opened lane—position which may be input on an interface device of one of the control circuits. Also, it is known to provide sensor elements on the shelf units, to detect if any object or person would hinder the displacement of each shelf unit, especially in the opened lane between two shelf units. The control circuits will allow interaction of these sensor devices to help prevent the shelf units from accidentally crushing an object or a person. The network cables conventionally run along and are supported by the wire support arms, next to the power cords.
The problem with the above-mentioned method of supporting the power cords and the network cables is that the wire support arms are cumbersome, require space in a shelving system that aims to optimize space, and are aesthetically undesirable.